Bleeding during and after intercourse

I have been bleeding occasionally during or after intercourse. I have a 9 month old daughter, and I am 22. It took eight months for my period to return, and I had irregular periods before getting pregnant. For about two months I have been spotting and bleeding during or after intercourse. I had a pap smear that came back normal, I also had a pelvic ultrasound just to be sure and that came back normal. The Doc tested for testosterone and that came back normal. Occasionally I have a cramping feeling during sex. Usually I only bleed a little but today it was a lot. Should I be concerned or is this just my body trying to return to normal after the baby. I am no longer nursing and stopped nursing at two months.